1. Field of the Invention
The present invention relates generally to a new intermodal railway car having the substantial benefits of a reduced profile vertically and laterally that will meet the plate B requirements of the Association of American Railroads while carrying a variety of over the highway vehicle trailers and cargo containers for railway transport. More specifically, the present invention relates to a design for intermodal railway car utilizing the substantial cost savings of sharing standard railway trucks by articulated connections between two or more or such intermodal railway cars while having the substantial structural integrity of extended side sills and stub center sills to provide a depressed center structure for the carrying of a variety of highway vehicle trailers and cargo containers for railway transport.
2. Description of the Prior Art
With the advent of interstate highway systems, over the highway vehicle travel for the transport of goods to and from the marketplace has become a substantial portion of the transport service volume from domestic manufacturers and suppliers. With the more recent energy crunch causing the cost of the fuel for the operation of such vehicular traffic to rise substantially thus increasing the cost of such mode of transportation for goods, ways have been sought to utilize the more effective means of railway transport of such goods. It has been found that an effective mix of railway and over the highway vehicles would be one where the railway is utilized to transport the goods over the long distances ending at stations whereby the over the highway vehicles can deliver the goods to the nearby areas not directly served by railway spur lines. Thus, the search for railway vehicles or railway cars that would be capable of carrying such over the highway vehicle trailers and containers began.
As early as the 1950's, such designs began to be seen in the patent literature and exemplified by U.S. Pat. Nos. 2,638,852; 2,971,478; 3,051,089; 3,102,497; 3,102,646; 3,151,575; 3,238,899; 3,223,052, 3,313,246 and 4,233,909. All of these cited references have one common theme in that the idea was to utilize over the highway vehicle trailers and containers to ship the goods but allowing them to transport over the railway system for long distances for the economies that could be derived therefrom. Of these designs, one of the major drawbacks was that in each case there was a central structural member necessary for the maintenance of the structural integrity of the units for such railway travel and as a result thereof, these units had difficulty in terms of carrying wheeled over the highway vehicle trailers due to the restrictive clearances for the railway system.
The early designs utilize a flatbed concept and generally one railway car on a set of two trucks thus the substantial burden of producing two sets of trucks for each railway car in accordance with the prior art. As it became apparent that these prior art designs had very limited capabilities in terms of the selection of various over the highway vehicle trailers and containers that they could carry and still meet the height requirements of the Association of American Railroads (referred to as AAR) for the transport on the American railway system, more recent designs began to evolve in which a depressed center portion was utilized in order to lower the overall height of such railway cars.
U.S. Pat. No. 3,357,371 was such a later development wherein the attempt was made to depress the center of the railway car to accomplish an overall lowering of the height of the container or over the highway vehicle trailers with wheels on it so as to more amply comply with the height requirements for operation on the railway system. Some of the problems associated with this design include the fact that the structure is complicated and thus more costly to construct and that the length of the lowered space for the acceptance of cargo containers or the rubber tired vehicle trailers is limited which limits the usefulness of the railway car for carrying forty-five foot trailers. Also this car in each case utilizes two railway trucks for its support and thus does not accomplish the cost savings as might be desired for a long container train.
A later design was found in U.S. Pat. No. 3,509,829 wherein a depressed center was used to provide a railway car which could contain highway vehicle trailers to be within the height requirements and did for the first time utilize two railway cars on one truck for what is generally referred to as an articulated connection. Some of the problems associated with this particular kind of car were the fact that the coupler height on this car was considerably lower than that of standard freight cars and thus if this railway car were to be put into a train containing a mixture of freight cars and these railway cars an elevator coupler mechanism was necessary to achieve equal height with the couplers of other standard cars. Also, the articulated connection of this kind of car was extremely limited in terms of the angular diposition available for cornering of the car around sharp curves that might result in certain portions of the U.S. railway track system.
Thus, these present designs have been found inadequate for many reasons but particularly for: the lack of an articulated connection which provides a coupler height equal to that of the standard car, that the depressed center portion of the car limits significantly the range of various types of containers or highway vehicle trailers that might be used on such railway cars, and the problem of carrying forty-five foot trailers